The present invention relates to a data recorder for recording data into a cassette tape unit and a data reader for reading-out the recorded data. More particularly, the present invention relates to a data recorder for recording check data and true data into a cassette tape unit and a data reader for reading out the true data with the help of the check data.
Recently, an audio cassette tape has been employed for storing data in the form of analog information useful for an electronic apparatus of a stored program system. In introducing data from the audio cassette tape to an entry means for the electronic apparatus, the data was taken out through earphone terminals connected to a sound volume adjustment circuit for a cassette tape deck. Therefore, adjustment of sound volume greatly affects the reliability of the data introduced.
A conventional audio cassette tape format comprised only a non-recorded section and a recorded section. Data were entered in the recorded section while an appropriate error check operation was being performed. If errors were detected, the operator was informed of the presence of the errors and directed to adjust sound volume with the help of only his perception, and to repeat the entry operation from the beginning.
That is, even using the conventional audio cassette tape format, it was difficult to adjust the amplitude for the sound volume, thereby resulting in inefficient data entry to a new cassette tape.